Dongwu Securities: Material changes and packaging process upgrades are approaching the tipping point of the industrialization of resonant glass substrates

The Zhitong Finance App learned that Dongwu Securities released a research report stating that it is focusing on domestic equipment and material opportunities in the industrialization of glass substrates along the three main lines of the “laser-lithography-electroplating” process. (1) Laser drilling/modification equipment: TGV drilling is a key process for glass substrates; (2) lithographic/direct writing equipment: RDL high-density wiring and photosensitive glass lithography; (3) electroplating equipment and electroplating chemicals: TGV copper filling and RDL electroplating are core value processes.

The main views of Dongwu Securities are as follows:

Increased demand for AI computing power is driving up bandwidth requirements. Glass substrates are expected to start a “material revolution” for advanced packaging, and equipment and materials in the industrial chain will be the first to benefit

In the post-Moore era, chip process dividends are slowing down, and advanced packaging has become a key path to improving system performance; according to Yole data, the global advanced packaging market is about US$46 billion in 2024, +19% YoY, and is expected to reach US$79.4 billion and a CAGR of about 9.5% in 2030. As the collaborative requirements of computing power chips and HBM high-bandwidth storage continue to increase, silicon-based and organic intermediary layers/carriers gradually hit bottlenecks in terms of large size, warpage control, and high frequency loss. Glass has become a disruptive material due to its inherent characteristics such as stable mechanical dimensions, adjustable CTE, low dielectric loss, flat surface, and panel-level large-scale processing. At present, industry consensus is being formed: Intel announced a breakthrough in mass production technology for glass core substrates at the 76th ECTC in 2026, TSMC promoted panel-level CoPos, Corning launched the Glass Bridge CPO program, BOE announced on May 20 that the glass-based sealed loading board test line has been connected and sent to customers for certification. Vogue Optoelectronics, Lansi Technology, etc. are also intensively deployed, and leading companies at home and abroad are jointly verifying the industrialization direction of glass substrates.

Three major solutions for glass substrates to gradually open up equipment and material space layer by layer

1) Panel-level packaging (CoPOS) solution: Glass is used as a square temporary carrier, carries Cowos-L RDL heavy wiring, uses TGV glass holes and metallizes to prepare RDL to be vertically interconnected by TGV; this solution is more economical than round wafers, supports large panel-level sizes, can adjust CTE to improve warpage, and can cut out embedded components to evolve a 5.5D package. 2) Glass core sealing plate solution: glass is used to replace the organic core layer of traditional copper-clad plate. Df has superior mechanical rigidity and dielectric loss than organic materials, and better satisfies high-frequency high-speed transmission. 3) CPO Glass Bridge Solution (Corning): An optical waveguide is made inside the glass, directly connected to the PIC and optical fiber, replacing FAU, significantly reducing the difficulty of coupling alignment, and can be combined with the glass substrate process. What the three main lines have in common is that they focus their value on leading graphics and copper plating processes such as TGV drilling, metallized electroplating, and RDL wiring.

Core increments are in processing equipment and materials

TGV drilling (laser/etching), metallization and electroplating, and RDL lithography are the three key processes in the industrialization of glass substrates. TGV holes use laser drilling (UV ultrafast lasers are superior to CO), laser-induced modification+wet etching, and photosensitive glass lithography; metallization uses magnetron sputtering seed layers with chemical plating/electroplating to achieve full copper filling; RDL follows silicon-based electroplating methods and Damascus methods, which place higher demands on direct writing lithography, vertical electroplating, and electroplating chemicals. Currently, bottlenecks focus on forming holes with a high depth-to-width ratio, no gap filling in electroplating, and glass cracking control. This is the window period for domestic equipment and materials companies to enter.

Risk warning: Downstream giants' glass substrate introduction progress falls short of expectations; key process yield breakthroughs fall short of expectations; demand for advanced packaging and AI computing power falls short of expectations.